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Tag Archives: 2013

This image from the Solar Dynamics Observatory shows the X6.9 solar flare of Aug. 9, 2011 near the western limb (right edge) of the sun. CREDIT: NASA/SDO/Weather.com

Solar flares like the huge one that erupted on the sun early today (Aug. 9) will only become more common as our sun nears its maximum level of activity in 2013, scientists say.

Tuesday’s flare was the most powerful sun storm since 2006, and was rated an X6.9 on the three-class scale for solar storms (X-Class is strongest, with M-Class in the middle and C-Class being the weakest).

Flares such as this one could become the norm soon, though, as our sun’s 11-year cycle of magnetic activity ramps up, scientists explained. The sun is just coming out of a lull, and scientists expect the next peak of activity in 2013. The current cycle, called Solar Cycle 24, began in 2008.

“We still are on the upswing with this recent burst of activity,” said Phil Chamberlin, a solar scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md., who is a deputy project scientist for the agency’s Solar Dynamics Observatory, a sun-studying satellite that launched in February 2010. “We could definitely in the next year or two see more events like this; there’s a potential to see larger events as well.”

A more active sun

Earth got lucky with the most recent flare, which wasn’t pointed directly at Earth; therefore, it didn’t send the brunt of its charged particles toward us, but out into space. However, we may not be so fortunate in the future, experts warned.

“We’re in the new cycle, it is building and we’ll see events like this one,” said Joe Kunches, a space scientist with the National Oceanic and Atmospheric Administration (NOAA)’s Space Weather Prediction Center. “They’ll be much more commonplace and we’ll get more used to them.”

Spacecraft such as the Solar Dynamics Observatory (SDO), which recorded amazing videos of the Aug. 9 solar flare, and other observatories will be vital in monitoring the sun during its active phase, researchers said.

How sun storms form

Storms brew on the sun when pent-up energy from tangled magnetic field lines is released in the form of light, heat and charged particles. This can create a brightening on the sun called a flare, and is also often accompanied by the release of a cloud of plasma called a coronal mass ejection (CME).

These ejections are the part we Earthlings have to worry about.

As the CME careens through space, it can send a horde of charged particles toward our planet that can damage satellites, endanger astronauts in orbit, and interfere with power systems, communications and other infrastructure on the ground.

“We’re well aware of the difficulties and challenges,” Kunches told SPACE.com. “We know more about the sun than we ever have.”

Can we predict solar storms?

When a big storm occurs, the Space Weather Prediction Center releases a warning to the U.S. Department of Homeland Security, emergency managers and agencies responsible for protecting power grids. Then power grids can distribute power and reduce their loads to protect themselves.

Satellite and power companies are also trying to design technology that can better withstand the higher radiation loads unleashed by solar storms.

Still, scientists would like to offer more advanced warnings when big storms are headed our way.

“We’re being reactive, we’re not being proactive,” Chamberlin said. “We don’t know how to predict these things, which would be nice.”

Chamberlin said solar science has come a long way in recent years, though, and the goal of SDO and other NASA projects is to improve our understanding of the sun and our ability to forecast space weather.

You can follow SPACE.com senior writer Clara Moskowitz on Twitter @ClaraMoskowitz. Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook.

Scientists call for plans to change asteroid’s path.
Developing technology could take decades.

Alok Jha
The Guardian, Tuesday 6 December 2005

In Egyptian myth, Apophis was the ancient spirit of evil and destruction, a demon that was determined to plunge the world into eternal darkness.

A fitting name, astronomers reasoned, for a menace now hurtling towards Earth from outerspace. Scientists are monitoring the progress of a 390-metre wide asteroid discovered last year that is potentially on a collision course with the planet, and are imploring governments to decide on a strategy for dealing with it.

Nasa has estimated that an impact from Apophis, which has an outside chance of hitting the Earth in 2036, would release more than 100,000 times the energy released in the nuclear blast over Hiroshima. Thousands of square kilometres would be directly affected by the blast but the whole of the Earth would see the effects of the dust released into the atmosphere.

And, scientists insist, there is actually very little time left to decide. At a recent meeting of experts in near-Earth objects (NEOs) in London, scientists said it could take decades to design, test and build the required technology to deflect the asteroid. Monica Grady, an expert in meteorites at the Open University, said: “It’s a question of when, not if, a near Earth object collides with Earth. Many of the smaller objects break up when they reach the Earth’s atmosphere and have no impact. However, a NEO larger than 1km [wide] will collide with Earth every few hundred thousand years and a NEO larger than 6km, which could cause mass extinction, will collide with Earth every hundred million years. We are overdue for a big one.”

Apophis had been intermittently tracked since its discovery in June last year but, in December, it started causing serious concern. Projecting the orbit of the asteroid into the future, astronomers had calculated that the odds of it hitting the Earth in 2029 were alarming. As more observations came in, the odds got higher.

Having more than 20 years warning of potential impact might seem plenty of time. But, at last week’s meeting, Andrea Carusi, president of the Spaceguard Foundation, said that the time for governments to make decisions on what to do was now, to give scientists time to prepare mitigation missions. At the peak of concern, Apophis asteroid was placed at four out of 10 on the Torino scale – a measure of the threat posed by an NEO where 10 is a certain collision which could cause a global catastrophe. This was the highest of any asteroid in recorded history and it had a 1 in 37 chance of hitting the Earth. The threat of a collision in 2029 was eventually ruled out at the end of last year.

Alan Fitzsimmons, an astronomer from Queen’s University Belfast, said: “When it does pass close to us on April 13 2029, the Earth will deflect it and change its orbit. There’s a small possibility that if it passes through a particular point in space, the so-called keyhole, … the Earth’s gravity will change things so that when it comes back around again in 2036, it will collide with us.” The chance of Apophis passing through the keyhole, a 600-metre patch of space, is 1 in 5,500 based on current information.

There are no shortage of ideas on how to deflect asteroids. The Advanced Concepts Team at the European Space Agency have led the effort in designing a range of satellites and rockets to nudge asteroids on a collision course for Earth into a different orbit.

No technology has been left unconsidered, even potentially dangerous ideas such as nuclear powered spacecraft. “The advantage of nuclear propulsion is a lot of power,” said Prof Fitzsimmons. “The negative thing is that … we haven’t done it yet. Whereas with solar electric propulsion, there are several spacecraft now that do use this technology so we’re fairly confident it would work.”

The favoured method is also potentially the easiest – throwing a spacecraft at an asteroid to change its direction. Esa plans to test this idea with its Don Quixote mission, where two satellites will be sent to an asteroid. One of them, Hidalgo, will collide with the asteroid at high speed while the other, Sancho, will measure the change in the object’s orbit. Decisions on the actual design of these probes will be made in the coming months, with launch expected some time in the next decade. One idea that seems to have no support from astronomers is the use of explosives.

Prof Fitzsimmons. “If you explode too close to impact, perhaps you’ll get hit by several fragments rather than one, so you spread out the area of damage.”

In September, scientists at Strathclyde and Glasgow universities began computer simulations to work out the feasibility of changing the directions of asteroids on a collision course for Earth. In spring next year, there will be another opportunity for radar observations of Apophis that will help astronomers work out possible future orbits of the asteroid more accurately.

If, at that stage, they cannot rule out an impact with Earth in 2036, the next chance to make better observations will not be until 2013. Nasa has argued that a final decision on what to do about Apophis will have to be made at that stage.

“It may be a decision in 2013 whether or not to go ahead with a full-blown mitigation mission, but we need to start planning it before 2013,” said Prof Fitzsimmons. In 2029, astronomers will know for sure if Apophis will pose a threat in 2036. If the worst-case scenarios turn out to be true and the Earth is not prepared, it will be too late. “If we wait until 2029, it would seem unlikely that you’d be able to do anything about 2036,” said Mr Yates.

By Kat Piper
Epoch Times Staff
Created: March 30, 2012
Last Updated: April 4, 2012

Massive bursts of solar wind and magnetic fields from the Sun can cause huge sunquakes, according to new UK research.

The results of the study, led by University College London’s Mullard Space Science Laboratory, are being presented by Dr Sergei Zharkovat at the National Astronomy Meeting 2012 in Manchester on Friday, March 30.

Research over the last 10 years has shown that sunquakes can be produced when solar flares—huge explosions of energy in the Sun’s atmosphere—impact and travel into the Sun. The quakes appear as circular ripples on the surface of the Sun.

The new study shows that eruptions of charged particles and magnetic fields known as Coronal Mass Ejections (CMEs) are also able to produce sunquakes.

“Sunquakes are generated by solar flares, when enormous amounts of energy are released high up in the solar atmosphere. Most of the energy goes up into interplanetary space, but a fraction of this energy travels to the Sun’s surface creating a sonic boom that causes the solar interior to oscillate and produce the ripples,” explained Zharkov in an email.

“I sometimes think of sunquakes as thunder to the flare’s lightning, except imagine a lightning over an ocean that is so strong that it creates a tsunami.”

The researchers studied an eruption that took place on Feb. 15, 2011. They found that sunquakes 1,000 times more powerful than the March 2011 Japanese earthquake were triggered at two ends of the erupting rope of magnetic field. The sudden expansion of the magnetic field as it erupts is thought to play a part in the generation of the sunquakes.

The eruption travelled through our solar system at around 600 kilometres per second (1.34 million miles per hour) towards Earth, causing a geomagnetic storm and aurora when it hit the Earth’s atmosphere.

It is for this reason that study of sunquakes is of interest, especially as solar activity is predicted to increase and peak in 2013.

“Sunquakes themselves do not have [an] impact on Earth as they are acoustic waves travelling inside the Sun. But flares and, accompanying them, Coronal Mass Ejections that we have shown play an important role in generating sunquakes, can and do impact Earth,” Zharkov said.

“Sunquakes now form an integral part for our search for understanding of flare and CME phenomena.”

Flares and CMEs have a direct impact on space weather, so understanding how they form could help in predicting when they are going to occur and planning for possible geomagnetic storms, which can affect satellites and radio and GPS equipment on Earth.

But sunquakes are relatively rare, explained Zharkhov. “Known sunquakes were all generated by string solar flares (X and M class), which occur only during the active part of an [11-year] Solar Cycle. However, only a small fraction of such flares produce sunquakes,” he said.

“There is also a chance, however, that sunquakes are more common than we think; it’s just that our means of detecting them are not yet up to scratch.”

Until recently, observation of sunquakes had been hampered by availability of data. “With the (relatively) new NASA’s Solar Dynamics Observatory satellite providing us with practically continuous high resolution and high cadence observations of the Sun, this problem is now solved,” Zharkov said.

Much like geologists use earthquakes to understand the internal structure of our planet, future research will be focused on using sunquakes to learn more about the internal processes of the Sun, said Zharkov. As scientists still don’t fully understand how sunquakes are generated, research will also continue to look for physical explanations of this solar phenomenon.